International Geology Review, Vol. 48, 2006, p. 702–724.Copyright © 2006 by V. H. Winston & Son, Inc. All rights reserved.

Stratigraphy and Detrital Modes of Upper Messinian Post-evaporitic Sandstones of the Southern Apennines, Italy:

Evidence of Foreland-Basin Evolution during the Messinian Mediterranean Salinity Crisis

MIRKO BARONE, SALVATORE CRITELLI,1 EMILIA LE PERA,Dipartimento di Scienze della Terra, Università degli Studi della Calabria, 87036 Arcavacata di Rende (CS), Italy

SILVIO DI NOCERA, FABIO MATANO, AND MARIO TORRE

Dipartimento di Scienze della Terra, Università degli Studi di Napoli Federico II, Largo S. Marcellino 10, 80138 Napoli, Italy

Abstract

During the Messinian, the southern Apennines thrust belt experienced a period of strong tectonicrearrangement and accretion, activation of overthrusts, and consequent migration of depocenters.The upper Miocene successions cropping out in the northern segment of the southern Apenninethrust belt have good potential for improving our understanding of the interplay between Messiniansalinity-crisis events and foreland-basin evolution. The local Messinian stratigraphy includes: (1)pre-evaporitic thin-bedded euxinic marly clay, interbedded with diatomaceous marls; (2) evaporiticlimestone, crystalline gypsum, and reworked gypsum; (3) post-evaporitic deposits subdivided intotwo main units: the Torrente Fiumarella unit and the Anzano Molasse Formation that grade upwardinto ostracod-rich deposits (Lago-Mare facies). The evaporitic and post-evaporitic sequences areseparated by an angular unconformity. This paper deals with the stratigraphic and petrographicstudy of the post-evaporitic deposits. The Torrente Fiumarella unit includes lacustrine and alluvialconglomerates, quartzolithic sandstones containing abundant carbonate detritus, shale, andreworked clastic gypsum. The Anzano Molasse Formation includes thick-bedded deltaic to turbid-itic conglomerates and sandstones passing upward to thin-bedded turbidite sandstones and marly-clayey siltstones. Sandstones are quartzofeldspathic with variable proportions of sedimentary (bothcarbonate and siliciclastic) and plutonic detritus. In particular, two populations are present,plutonic-rich and mixed plutonic-sedimentary. Volcaniclastic layers, composed of dominantly vitricparticles (shards and pumice), are also interbedded within Anzano Molasse sandstones. The Anzanosuccession includes rare freshwater ostracods that increase in abundance in the uppermost Lago-Mare facies. The Lago-Mare facies deposits are represented by silty-marly clay with abundantOstracoda shells (Ilyocypris gibba, Cyprideis torosa and Candona sp.) and intrarenite having abun-dant intrabasinal carbonate particles (ooids, peloids, and bioclasts) and subordinate extrabasinalnoncarbonate and carbonate particles. The post-evaporitic sequences represent an infilled foredeepbasin, with a lacustrine environment progressively deepening and experiencing gravity resedimen-tation. Detrital modes document complex provenance relations from upper Messinian accretedterranes of the southern Apennines thrust belt. Post-evaporitic sandstones in the Irpinia-Dauniasector of the southern Apennines foreland-basin system record both the effects of the forelandtectonic evolution and the Messinian Mediterranean salinity crisis. They may represent alternativemodels for foreland-basin evolution during a restricted time in late Messinian, which can be appli-cable also in other portions of the circum-Mediterranean orogen.

IntroductionGeneral characteristicsDURING THE LATE Messinian, nonmarine (evaporiticand lacustrine) sedimentary basins developed in thecircum-Mediterranean orogenic belts (e.g., Butler

and Grasso, 1993; Cipollari et al., 1999b) during thesalinity crisis (i.e., Hsü et al., 1977), followed by theLago-Mare events (i.e., Bonaduce and Sgarrella,1999). Thrust accommodation, deep dissection ofthe thrust belt, and superimposed evaporite andLago-Mare sedimentation are recorded in the strati-graphic sections of the Messinian peri-Mediterra-nean foreland basins.1Corresponding author; e-mail: critelli@unical.it

0020-6814/06/886/702-23 $25.00 702

POST-EVAPORITIC SANDSTONES 703

Large portions of the southern Italian orogenicsystem (Fig. 1) include diverse Messinian evaporiticand post-evaporitic stratigraphic units in both fore-land basins and syn-rift basins related to the back-arc Tyrrhenian opening (Patacca and Scandone,1989; Cipollari et al., 1999a). The aim of this paperis to discuss lithostratigraphic, sedimentologic, andpetrostratigraphic relations during the Messiniansalinity crisis in the Irpinia-Daunia portions of thesouthern Apennines, as responses to both salinitycrisis-events and tectonostratigraphic evolution ofthe foreland-basin system. The Irpinia-Dauniaupper Messinian sequences record the space/timeevolution of depozones located between the unde-formed stable margin and orogenic margin of theforeland region during the salinity crisis. In particu-lar, study of the nonmarine Anzano and Fiumarellaunits provides useful lithostratigraphic and petro-logic data for interpretations of similar sedimentarybasins, illustrating interrelations between tectono-stratigraphic evolution of foreland-basin architec-ture and input of the salinity crisis (e.g., rates of

accretion and unroofing, base-level changes, andprovenance). Their close relations may representalternative models for foreland-basin evolutionduring a restricted time in the late Messinian, whichcan be applicable also in other portions of thecircum-Mediterranean orogen.

Stratigraphic relationships among Messinianpre-evaporitic, evaporitic and post-evaporitic deposits in the Mediterranean

The Mediterranean salinity crisis resulted indeposition of a huge volume of Messinian evaporiticsediments, characterized by two major cycles(Lower Evaporites and Upper Evaporites), separatedby a deeply incised erosional surface related to thedrawdown of the Mediterranean Sea (Hsü et al.,1973, 1977; Müller and Mueller, 1991; Krijgsmanet al., 1999). The evaporites are overlain in severalMediterranean sites by Lago-Mare post-evaporiticfacies, which are mostly represented in many of theMediterranean basins by siliciclastic deposits thatcontain fresh- to brackish-water fauna. In some sites

FIG. 1. Tectonic sketch-map of the southern Apennines.

704 BARONE ET AL.

(e.g., the northern Apennines), Upper Evaporitesare not present and post-evaporitic deposits directlyoverlie Lower Evaporites.

During the Messinian salinity crisis, the coevalstratigraphic successions suggest a relatively homo-geneous depositional setting in Italy and in manyparts of the Mediterranean, as lithology and faciesarrangement of both pre-evaporitic deposits and pri-mary evaporites of the Apennine foredeep and otherMediterranean basins are similar. The sedimentaryrecord of the Lago-Mare differs among basins inthickness, ranging from a few meters to several-hundred meters, in facies (widely variable fromlacustrine to alluvial), and in composition, althoughsiliciclastics predominate. For example, post-evaporitic sequences include several formations inthe diverse districts of the Apennines-SicilianMaghrebian chains: “di tetto” and Cusercoli forma-tions, previously named as Colombacci Formation(Bassetti et al., 1994; Roveri et al., 1998, 2003) inthe northern Apennines; the Arenazzolo Formationin Sicily (Decima and Wezel, 1973) and its equiva-lent in southeastern Calabria (Cavazza and DeCelles, 1998), and the Anzano Molasse andFiumarella units in the Campanian Apennines(Matano, 2002; Matano et al., 2005).

A main problem concerning the Messinian salin-ity crisis is represented by stratigraphic relation-ships of the evaporites with both the underlying pre-evaporitic deposits and the overlying post-evaporiticdeposits, both in central basins and in peripheralbasins of the Mediterranean. The evaporites in mostcases conformably overlie the pre-evaporitic depos-its both in marginal basins and in the center of theMediterranean (Clauzon et al., 1996; Krijgsman etal., 1999). Only in the Sorbas basin (southeastSpain), some authors (e.g., Martin and Braga, 1994;Riding et al., 1998, 1999) have suggested that anerosional unconformity separates the evaporitesfrom the underlying pre-evaporitic marls; theycorrelated it to the sea-level drop that led to evapor-ite deposition in the Mediterranean center. Anerosional unconformity between the pre-evaporiticand evaporitic units has been recognized also inAlmerìa-Nìjar basin (Aguirre and Sànchez-Almazo,2004).

In several sectors of the circum-Mediterraneanthrust belts, the transition from evaporitic to post-evaporitic deposits is conformable, although thecontact is erosional in Cyprus (Orszag-Sperber etal., 2000; Rouchy et al., 2001), Sicily (Decima andWezel, 1973), Crete (Delrieu et al., 1993) and Vera

basin (southeastern Spain, Fortuin et al., 1995). Incontrast, the contact is continuous and gradual inmost internal basins of southern Spain (Sorbas,Murcia, Almerìa-Nìjar basins; Playà et al., 2000;Aguirre and Sànchez-Almazo, 2004).

In the Apennines foreland-basin system, post-evaporitic deposits unconformably cover evaporitesequences, as the result of a Messinian regionaltectonic phase (Ciaranfi et al., 1973; Elter et al.,1975; Di Nocera et al., 1976; Colalongo et al., 1978;Roveri et al., 2003), whereas in Sicily, the angularunconformity is located between the Lower Evapor-ites and the Upper Evaporites (Decima and Wezel,1971). In fact, the Arenazzolo Formation in Sicily(Decima and Wezel, 1971) postdates the UpperEvaporites, whereas the Colombacci Formation inthe northern Apennines is equivalent to the UpperEvaporites (Hsü et al., 1973; Colalongo et al., 1978;Vai, 1997).

In the Irpinia-Daunia Mountains area (southernApennines) evaporitic and post-evaporitic Messin-ian successions are well exposed. We present newstratigraphic and petrologic data, which lead to abetter understanding of tectonic evolution andpaleonvironmental conditions of post-evaporiticdeposits of the study area in the framework of lateMessinian events in the Mediterranean basin.

Geological Setting

The southern Apennines thrust belt (Fig. 1) ispart of the Africa-verging circum-MediterraneanApennine-Maghrebides orogenic belt. It resultsmainly from progressive NE-vergent thrusting ofMesozoic–Tertiary sedimentary units over theApulian foreland. The belt is associated with theTyrrhenian backarc basin to the southwest andthe Bradano foredeep to northeast. The Apulianforeland is represented by a Mesozoic–Cenozoiccarbonate platform, which is stratigraphically cov-ered in the southwestern flexured margin by terrige-nous deposits of the Pliocene–Pleistocene Bradanoforedeep (D’Argenio et al., 1975; Mostardini andMerlini, 1986; Doglioni, 1991; Roure et al., 1991).

The pre-orogenic Apulian continental marginconsists of pelagic basins and carbonate platforms,spanning the Triassic to the Miocene (D’Argenio etal., 1975; Mostardini and Merlini, 1986), whichwere gradually covered during the Miocene to EarlyPleistocene by deep-marine to continental forelandclastic wedges related to progressive flexure of litho-sphere beneath the advancing Apenninic thrust belt

POST-EVAPORITIC SANDSTONES 705

FIG

. 2. G

eolo

gica

l map

of t

he I

rpin

ia-D

auni

a se

ctor

of t

he s

outh

ern

Ape

nnin

es, I

taly

(mod

ified

afte

r M

atan

o et

al.,

200

5).

706 BARONE ET AL.

and cratonward shifting of the Apennine foredeep(Patacca et al., 1990, Sgrosso, 1998; Critelli, 1999).

After the Tyrrhenian backarc rifting, a signifi-cant shift of the foreland-basin system toward theENE occurred from Late Tortonian to Early–MiddlePleistocene (Patacca et al., 1990; 1993). During thelate Messinian, the Mediterranean salinity crisisproduced a wide diffusion of evaporitic to non-marine sedimentary basins both along the Tyrrhen-ian border of the chain and in foredeep-forelandsectors of the southern Apennines.

The study area falls in the Irpinia-Daunia sectorlocated in eastern margin of the northern part of thesouthern Apennines (Fig. 1). A complex imbricatedsystem occurred within the studied sector of thethrust belt (Fig. 2), formed by Middle Triassic toUpper Miocene shallow-marine to deep-marinecarbonate and pelagic successions of the Frigento,Fortore, Daunia and “Vallone del Toro” tectonicunits (see for a more complete description Matano etal., 2005; and Basso et al., 2002). Upper Messinian(Altavilla Basin) and Lower Pliocene (Ariano IrpinoBasin) thrust-top-basin clastic sequences are wide-spread in the study area (D’Argenio et al., 1975;Basso et al., 2002; Ciarcia et al., 2003) and illus-trate the progressive eastward migration of deforma-tion and accretion of tectonic units. Thesesequences progressively cover Mesozoic andTertiary deposits of Frigento, Fortore, Daunia, andVallone del Toro tectonic units (Fig. 2), which arefolded and thrust eastward over the buried Apulianthrust system (Roure et al., 1991; Pescatore et al.,2000; Matano and Di Nocera, 2001; Basso et al.,2002).

During the salinity crisis, the Frigento andFortore units were already assembled within thethrust belt, while Daunia and Vallone del Toro unitswere located in the undeformed foreland region(Basso et al., 2002; Di Nocera et al., 2002) withinthe Daunia unit (Monte Castello Evaporites Forma-tion) and the Vallone del Toro unit. Evaporiticdeposits are conformably present only withinDaunia and Vallone del Toro units, and were depos-ited before their tectonic deformation. Conse-quently, evaporite deposition can be referred toforedeep and forebulge depozones.

The Anzano and Fiumarella post-evaporitic unitsare characterized by dominantly coarse-grainedstrata with lacustrine and alluvial facies (Dessau,1952; Crostella and Vezzani, 1964; Basso et al.,2001, 2002; Matano, 2002). They represent syn-

orogenic deposits unconformably covering the fourtectonic units exposed in the study area (Fig. 2).

Methods and Petrography

Stratigraphic studies, detailed mapping (at1:10,000 scale), and sample collection were carriedout in the study area (Fig. 2) to detail the strati-graphic evolution of sedimentary sequences and toillustrate tectono-stratigraphic evolution of syn-orogenic basins in the Irpinia-Daunia sector of thesouthern Apennines during the Messinian salinitycrisis. Stratigraphic sections of Messinian post-evaporitic formations were studied to provide adetailed stratigraphic framework for petrographicalanalyses; gypsum facies have been previously stud-ied and discussed by Matano et al. (2005).

Twenty-eight medium-to-coarse-grained sand-stone samples from upper Messinian successionswere selected for thin-section analysis. About 500points were counted for each thin section (etchedand stained for plagioclase and potassium feldspar)according to the Gazzi-Dickinson method (Gazzi,1966; Dickinson, 1970; Ingersoll et al., 1984; Zuffa,1985). Point-count results and recalculated parame-ters are shown, respectively, in Tables 1 and 2.

Sandstones include abundant quartz as mono-crystalline and polycrystalline grains, the formerwith tectonic fabric (metamorphic grains withcrenulate subgrain boundaries) and without tectonicfabric (sedimentary or volcanic nature). Both plagio-clase and K-feldspar (orthoclase, microcline, andperthite) also represent important components;plagioclase is commonly altered to sericite. Bothplagioclase and k-feldspar are present as singlecrystals and in plutonic or rarely metamorphic phan-eritic rock fragments. Coarse-grained plutonic rockfragments include mainly granodiorite, but graniticfragments are also present. Fine-grained lithic frag-ments are mainly sedimentary, represented by chert,siltstone, shale, and extrabasinal carbonates asmicrite, biomicrite, sparitic and biosparitic lime-stones; metasedimentary (mainly fine grained schistand phyllite); ophiolitic lithic fragments are rare,whereas volcanic fragments having microlitic andfelsitic textures are minor.

The diagenetic phases in order of decreasingabundance, are: patchy calcite cement, pore-fillingcalcite, poikilotopic calcite, and calcite partlyreplacing quartz and feldspar.

POST-EVAPORITIC SANDSTONES 707

Messinian Stratigraphy in theIrpinia-Daunia Mountains

In the study area, the Daunia unit mainly recordsthe interplay between foreland-basin tectono-strati-graphic evolution and salinity-crisis events. Threeintervals can be distinguished in the Messinian suc-cession: (1) pre-evaporitic; (2) evaporitic; and (3)post-evaporitic (Fig. 3).

Pre-evaporitic intervalThe pre-evaporitic interval (Fig. 3), up to 30 m

thick, comprises thin-bedded laminitic dark-greymarly clays and marls, interbedded with light-greyash layers and whitish marly diatomites containing

fish scales (Matano et al., 2005). The depositionalenvironment was probably an anoxic pelagic starvedbasin, similar to other typical pre-evaporitic succes-sions (e.g., Dazzaro et al., 1988; Vai, 1997; Bellancaet al., 2001), the lack of significant exposures doesnot permit verification if the diatomite-bearingsuccession displays a cyclical pattern as in Sicily(Bellanca et al., 2001). The diatomites overlie bothbase-of-slope to basin calcarenite, calcilutite, andmarly clay strata (Faeto Formation), and pelagicclayey marls (“Toppo Capuana” clayey marl Forma-tion). A volcaniclastic layer locally marks the transi-tion between pre-evaporitic and evaporiticsuccessions; two other volcaniclastic layers areabove and below the transition (Fig. 3). The transi-

FIG. 3. Schematic stratigraphic column of the Messinian succession cropping out in the Irpinia-Daunia Mountains(modified after Matano et al., 2005).

708 BARONE ET AL.

TAB

LE 1

. Pet

rogr

aphi

c R

esul

ts o

f Mod

al A

naly

sis1

Anz

ano

Mol

asse

Uni

tT.

Fiu

mar

ella

Uni

tLa

go-m

are

Petr

ogra

phic

cla

sses

01-SC 528

01-SC 547

01-SC 523

01-SC 520

01-SC 529

01-SC 548

01-SC 527

01-SC 522

01-SC 525

01-SC 536

01-SC 533

01-SC 530

01-SC 526

01-SC 521

01-SC 531

01-SC 535

01-SC 546

01-SC 532

01-SC 550

01-SC 534

01-SC 549

01-SC 565

01-SC 544

01-SC 566

01-SC 567

01-SC 543

01-SC 538

01-SC 539

NC

E

Q

Qua

rtz

(sin

gle

crys

tals

)10

611

210

289

123

8590

8790

127

126

7693

9191

115

123

104

103

174

115

147

105

124

114

190

3146

Poly

crys

talli

ne q

uart

z w

ith te

cton

ite fa

bric

101

62

46

74

41

45

53

1114

49

35

21

177

7

Poly

crys

talli

ne q

uart

z w

ithou

t tec

toni

te fa

bric

25

61

11

11

22

612

1011

810

104

59

810

Qua

rtz

in m

etam

orph

ic R

.F.

175

1115

146

1110

51

13

58

12

16

66

31

Qua

rtz

in p

luto

nic

R.F

.50

3529

2641

2946

3419

3024

2113

177

247

54

106

3654

110

52

2

Qua

rtz

in p

luto

nic

or g

neis

sic

R.F

.1

31

11

Cal

cite

rep

lace

men

t on

quat

rz34

2426

4526

3625

2933

4932

2126

2546

946

3427

1024

1929

104

292

K

K-f

elds

par

(sin

gle

crys

tals

)73

7151

6250

4767

4446

5779

5567

4039

6468

5128

6556

1345

217

167

17

K-f

elds

par

in m

etam

orph

ic R

.F.

11

1

K-f

elds

par

in p

luto

nic

R.F

.30

3120

2437

815

1219

56

1513

310

2715

73

1912

345

61

31

2

Cal

cite

rep

lace

men

t on

K-f

elds

par

1213

47

45

101

45

21

513

71

163

113

91

81

5

P

Plag

iocl

ase

(sin

gle

crys

tals

)53

4331

2049

4656

4752

7889

6679

7537

9759

4440

9551

954

138

216

Plag

iocl

ase

in v

olca

nic

R.F

. 1

Plag

iocl

ase

in m

etam

orph

ic R

.F.

32

11

12

1

Plag

iocl

ase

in p

luto

nic

R.F

. 29

3514

2334

1114

1322

1513

2917

1419

5223

47

298

414

56

1

Plag

iocl

ase

in p

luto

nic

or g

neis

sic

R.F

. 1

Cal

cite

rep

lace

men

t on

Plag

iocl

ase

68

45

106

131

812

811

168

244

87

168

123

21

1

M

Mic

as a

nd c

hlor

ite (s

ingl

e cr

ysta

ls)

101

49

116

96

39

155

49

825

135

735

112

1

Mic

as a

nd c

hlor

ite in

vol

cani

c R

.F.

1

Mic

as a

nd c

hlor

ite in

plu

toni

c R

.F.

22

11

11

Mic

as a

nd c

hlor

ite in

plu

toni

c or

gne

issi

c R

.F

1

Mic

as a

nd c

hlor

ite in

met

amor

phic

R.F

. 1

11

L

Volc

anic

lith

ic w

ith m

icro

litic

text

ure

2

Volc

anic

lith

ic w

ith fe

lsiti

c gr

anul

ar te

xtur

e1

1

Phyl

lite

52

21

12

11

17

31

3

Fine

-gra

ined

sch

ist

41

14

77

12

21

12

56

POST-EVAPORITIC SANDSTONES 709Fi

ne-g

rain

ed s

ands

tone

1

Impu

re c

hert

33

31

31

12

2

Silts

tone

11

12

13

1

Met

aren

ite1

Shal

e1

11

34

122

110

15

Den

se m

iner

al (s

ingl

e cr

ysta

ls)

2

CE M

icri

tic li

mes

tone

34

529

442

539

253

228

2519

333

123

1824

406

6044

2710

5

Spar

itic

limes

tone

11

171

61

51

12

12

112

1

Mic

rosp

ariti

c lim

esto

ne1

171

71

115

13

42

16

11

911

267

36

Bio

spar

itic

limes

tone

215

21

Bio

mic

ritic

lim

esto

ne2

11

11

115

1336

4

Foss

il (s

ingl

e sk

elet

on)

12

12

11

215

6066

27

Sing

le s

par

(cal

cite

)1

32

21

21

Und

eter

min

ed li

mes

tone

125

61

32

1

Cl B

iocl

ast

333

203

Mx Si

licic

last

ic M

atri

x 2

210

26

217

119

85

310

151

206

1325

161

91

32

Car

bona

te M

atri

x20

1712

1317

184

3231

114

1835

2115

45

2721

2756

2739

2812

Cm C

arbo

nate

cem

ent (

pore

filli

ng)

3827

1032

3237

3113

2325

2925

1723

1517

1510

513

335

622

8821

3

Car

bona

te c

emen

t (pa

tchy

cal

cite

)21

6929

101

2130

6235

4435

2152

3443

391

1028

4640

8019

6290

53

Oxi

d-Fe

cem

ent

210

24

52

710

310

56

86

77

116

177

22

22

8

Qua

rtz

over

grow

th

12

Cal

cite

rep

lace

men

t on

unde

term

ined

gra

in4

531

2217

4118

4336

3735

4337

5589

2754

9110

84

746

1246

2754

Alte

rite

s2

11

1

Tota

l54

252

050

451

952

450

351

350

650

551

750

250

152

350

750

550

451

650

351

350

050

350

050

652

550

650

250

050

7

1 CE

= e

xtra

basi

nal c

arbo

nate

gra

ins;

CI

= in

trab

sina

l car

bona

te g

rain

s; N

CI

= in

trab

asin

al n

onca

rbon

ate

grai

ns; M

x =

mat

rix;

Cm

= c

emen

t; R

.F. =

coa

rse

grai

ned

rock

frag

men

ts; L

= li

thic

frag

men

ts; Q

= q

uart

z; K

= K

-fel

d-sp

ar; P

= p

lagi

ocla

se; M

= m

icri

te a

nd c

hlor

ite; N

CE

= e

xtra

basi

nal n

onca

rbon

ate

grai

ns.

710 BARONE ET AL.

TAB

LE 2

. Rec

alcu

late

d M

odal

Poi

nt, i

n pe

rcen

t1

Qm

FLt

Qt

FL

Qm

KP

Qp

Lvm

Lsm

LmLv

LsR

gR

vR

mR

gR

sR

mN

CE

CE

CI

P/F

T. F

ium

arel

la U

nit

01-S

C 5

6558

933

609

3187

76

50

950

010

091

09

2671

369

310

0.4

01-S

C 5

4448

484

5048

250

2525

500

5020

080

930

788

57

982

00.

501

-SC

545

6314

2367

1518

819

1021

079

00

100

670

3316

768

8218

00.

501

-SC

566

3812

5045

1243

7615

914

086

00

100

500

509

829

6040

00.

401

-SC

567

367

5740

753

856

97

093

00

100

710

298

893

5149

00.

6

X49

1833

5218

3076

1212

190

814

096

740

2629

656

7228

00.

5SD

±12

±17

±21

±11

±17

±20

±15

±8±8

±18

±0±1

8±9

±0±9

±18

±0±1

8±3

4±3

4±3

±19

±19

±0

Mol

asse

Anz

ano

Uni

t01

-SC

521

4346

1145

469

4819

3322

078

30

9770

030

4437

1992

80

0.6

01-S

C 5

2637

5211

3952

941

2534

170

839

091

772

2152

3414

937

00.

601

-SC

530

3550

1537

5013

4024

364

096

40

9688

012

5537

888

120

0.6

01-S

C 5

5348

511

4851

148

2329

00

100

00

100

980

292

62

991

00.

501

-SC

536

5345

254

442

5518

2833

067

00

1094

06

8312

598

20

0.6

01-S

C 5

2052

426

5442

455

3015

300

7023

077

770

2368

1220

973

00.

301

-SC

529

5045

551

454

5223

2518

973

5011

3978

121

754

2199

10

0.5

01-S

C 5

4845

3619

4736

1756

2123

110

892

098

790

2140

4911

8317

00.

501

-SC

527

4647

748

475

4926

2539

061

400

6072

127

6510

2598

20

0.5

01-S

C 5

2244

3323

4633

2158

2022

90

913

097

790

2139

5011

8020

00.

501

-SC

525

4244

1444

4412

4923

2811

089

20

9884

016

5337

1089

110

0.5

01-S

C 5

2342

3127

4531

2457

2617

110

891

099

780

2236

5410

7723

00.

401

-SC

528

4746

750

464

5028

2240

357

506

4474

125

715

2492

80

0.4

01-S

C 5

4744

515

4651

346

3123

330

6725

075

910

984

88

982

00.

401

-SC

531

4442

1447

4112

5220

2819

081

00

100

900

1047

476

900

100.

601

-SC

535

3558

741

581

3823

3985

015

250

7590

010

873

1099

10

0.6

01-S

C 5

4644

479

5047

349

2724

670

3367

033

660

3462

533

991

00.

501

-SC

532

46

3717

5137

1255

2421

280

7211

089

680

3229

5714

919

00.

501

-SC

550

4636

1852

3612

5618

2633

067

30

9758

042

2558

1793

70

0.6

01-S

C 5

3445

514

4851

147

2132

870

130

010

095

05

923

510

00

00.

601

-SC

549

4344

1348

448

5026

2436

064

100

9076

024

4344

1393

70

0.5

X44

4412

4744

950

2426

301

6916

183

790

2142

4612

937

00.

5SD

±5±7

±8±5

±7±7

±6±4

±6±2

4±2

±24

±21

±3±2

2±1

0±1

±10

±10

±9±4

±7±7

±0X

78

715

SD±1

1±3

±11

Lago

-mar

e01

-SC

-538

5122

2751

2227

6916

150

010

026

074

310

6915

5233

144

820.

501

-SC

-539

5227

2154

2719

6625

910

585

305

6533

858

1754

2929

467

0.3

X52

2524

5325

2368

2012

53

9328

370

324

6416

5331

224

7474

0.4

SD±1

±4±4

±2±4

±6±2

±6±4

±7±4

±11

±3±4

±6±1

±6±8

±1±1

±3±1

1±0

±11

1 X =

mea

n; S

D =

sta

ndar

d de

viat

ion.

Gra

in p

aram

eter

s: Q

m =

mom

ocry

stal

line

quar

tz; Q

p =

poly

cris

talli

ne q

uart

z; Q

t = Q

m +

Qp;

K =

K-f

elds

par;

P =

Pla

gioc

lase

; F =

P +

K; L

= a

phan

itic

lithi

c gr

ains

; Lt =

L +

Qp

+ C

E;

Lvm

= v

olca

nic

and

met

avol

cani

c; L

sm =

sed

imen

tary

and

met

ased

imen

tary

lith

ics

frag

men

ts; N

CE

= n

on-c

arbo

nate

ext

raba

sina

l gra

ins;

CE

= c

arbo

nate

ext

raba

sina

l gra

ins;

CI

= ca

rbon

ate

intr

abas

inal

gra

ins.

Sam

ples

01-S

C-5

38/5

39 h

ave

been

plo

tted

only

on

the

NC

E C

E C

I di

agra

m fo

r th

e co

rres

pond

ents

rec

alcu

late

d pa

ram

eter

s. T

he u

nder

lined

par

amet

ers

indi

cate

the

sam

ples

of t

he s

ubpe

trof

acie

s of

Anz

ano

Mol

asse

in th

e R

g-R

s-R

m

tria

ngul

ar p

lot.

POST-EVAPORITIC SANDSTONES 711

tion is marked by a sharp change in lithology frompelagic euxinic pelitic facies into evaporites, char-acterized by stratal conformity.

Evaporitic interval

The evaporitic interval, represented by theMonte Castello Evaporites Formation (Crostella andVezzani, 1964), comprises laterally discontinuousevaporitic limestone and gypsum beds. The MonteCastello Evaporite Formation, whose exposed thick-ness ranges from a few meters to about 50 m,conformably overlies the Lower Messinian portion ofthe Toppo Capuana clayey marl and Faeto forma-tions (Fig. 3).

Evaporitic limestones, which locally representthe entire evaporitic succession, are massive orlaminated, and made of micrite and dolomicrite withmillimetric gypsum and sulfur crystals, spongespicules, and desiccation cavities, such as birdseyesand fenestrae (Dazzaro et al., 1988).

Several types of alternating gypsum lithofaciesoccur, such as selenites, laminated and nodular-laminated gypsum, and coarse clastic gypsum(Matano et al., 2005), with bed thickness rangingfrom a few centimeters up to 10 m.

Thick beds of coarse clastic gypsum (gypsruditesand gypsarenites) constitute the main part of theevaporite succession. Gypsarenites are commonlygraded, with cross-bedded or rippled intervals;gypsrudites are formed from up to 10 m thick bedsof massive or graded breccias in a sandy matrix,with pebbles including various gypsum lithofacies,limestone, and clay chips. They are interbeddedwith fine-grained clastic gypsum. Laminatedgypsum consists of evenly (mm-scale) laminatedlayers, both clastic and crystalline. The layers mayshow small-scale enterolithic folding and laterallylinked hemispheroidal stromatolitic structures(Dazzaro et al., 1988). Layers of coalescent whitishgypsum nodules (up to 3 cm) are commonly associ-ated with laminated gypsum, forming massive bedsup to 5m thick.

Beds of coarse clastic gypsum are gravity-flowdeposits derived from intrabasinal reworking. Theymay have been deposited in both shallow- and deep-water environments. Gypsarenite and gypsrudite areinterpreted as turbidites and debrites respectively;the occurrence of gypsum turbidites and debrisflows does not necessarily indicate a great waterdepth, but does indicate relief within the basin(Matano et al., 2005). The very fine grained clasticlaminated gypsum, intercalated within turbiditic

graded gypsarenites, could suggest a somewhatdeeper subaqueous environment of deposition. Withreference to the nodular-laminated gypsum litho-facies, a late diagenetic origin of the nodular struc-tures, linked with partial anhydritization of gypsum,is supposed for the association with subaqueousstructures and the presence of distortion in adjacentgypsum layers produced by nodule growth (Ciar-apica and Passeri, 1980; Peryt, 1996). Crystallinegypsum is exposed as beds of shallow-tail twincrystals and acicular and granular massive gypsumlayers. Selenitic gypsum and microcrystalline lami-nated gypsum strata can be generally attributed to ashallow-subaqueous environment (Schreiber andDecima, 1976; Schreiber et al., 1976; Vai and RicciLucchi, 1977; Matano et al., 2005).

Post-evaporitic interval

The Monte Castello Evaporites Formation isunconformably capped by post-evaporitic clasticdeposits; the unconformity commonly is marked bydesiccation cracks in both gypsum and evaporiticlimestone, suggesting subaerial exposure. The post-evaporitic interval is represented by two units: theTorrente Fiumarella unit and the Anzano Molasse(Fig. 3). Post-evaporitic successions overlie withangular unconformity the Daunia unit, which wastectonically deformed during the intra-Messiniantectonic phase. Late Messinian post-evaporiticsequences are unconformably covered by Pliocenestratigraphic successions (Amore et al., 1998) of theAriano Supersynthem, which is formed by alluvial,nearshore, and neritic clastic facies associations(Ciarcia et al., 2003).

Lithofacies and Detrital Modes of the Post-Evaporitic Units

Eight detailed stratigraphic sections of post-evaporitic sequences are shown in Figure 4. TheTorrente Fiumarella unit is characterized by clasticcontinental (lacustrine and alluvial) facies (Basso etal., 2001, 2002), with variable thickness from 50 to250 m. The lower interval is mainly coarse grained,the upper interval consists of pelitic and fine-grained arenitic deposits with lenses of silty sands,conglomerates, and reworked clastic gypsum. Theunit is characterized by an overall upward finingtrend, and its sedimentary features are character-ized by strong lateral discontinuity (Fig. 4).

Along the Fiumarella River, the TorrenteFiumarella unit shows different facies and thick-

712 BARONE ET AL.

FIG

. 4. S

trat

igra

phic

logs

of t

he p

ost-

evap

oriti

c de

posi

ts. T

he lo

catio

n of

the

sect

ions

is s

how

n in

Fig

ure

2.

POST-EVAPORITIC SANDSTONES 713

ness: thick coarse-grained strata in the proximalsector (near Flumeri; Fig. 2) are distally replaced bythin-bedded siltstone and mudstone. In the proximalsetting, the basal interval (Fig. 4, log I) mainlyconsists of disorganized, crudely stratified, hetero-

metric granular to pebbly conglomerates (Fig. 5A)with thick to very thick strata (up to 4 m). Lime-stones, marls, arenites, and granites form thepebbles, which are usually moderately to wellrounded with a scarce sandy matrix. Some layers of

FIG. 5. Field photographs showing some lithofacies of the post-evaporitic units (reference to Fig. 5 logs is given).Torrente Fiumarella unit: A. Channelled polymictic conglomerates (log I). B. Graded quartzolithic sandstones passing tosilty clays (log I). Anzano Molasse: C. Amalgamated massive sandy-matrix granule and pebbly conglomerates of Valle diFassa quarry (log VII). D. Detail of the texture of the conglomerates in photo C. E. Thin-bedded and laminated quartzo-feldspathic sandstones (log VII). F. Turbiditic quartzofeldspathic sandstones and clayey siltstones (log VI). G. Volcani-clastic layer (log VI).

714 BARONE ET AL.

brownish arenites and of greenish sandy pelites richin organic matter are present (Fig. 5B). North ofFlumeri (Fig. 2), between Fiego di S. Potito and S.Sofia, two mainly conglomeratic decametric bodiesare present; the upper one is characterized bymorphological relief and continuity for about 1.5km. Coarse-grained bodies are floored by erosionalsurfaces and exhibit a tabular geometry. They repre-sent hyperconcentrated-debris-flow deposition ina shallow-subaqueous environment; in the upperhorizon, embricated pebbles are also present. Theyare interpreted as different evolutionary stages of asmall fan-delta system prograding into a shallowlacustrine basin. They show a downcurrent transi-tion to turbidite sandstones (massive to graded andlaminated couplets), locally rich in a monospecificostracofaunal assemblage with Cyprideis torosa(Basso et al., 1996, 2001), representing a Lago-Maretype facies (Fig. 4, log I), here referred to theAnzano Molasse; in more distal strata, interbeddedlow-density fine-grained turbiditic sandstones andmudstones occur (Fig. 4, logs II-IV-V).

The upper interval, more developed in distal set-tings, is characterized by interbedded mudstones,marly limestones and thin-bedded fine-grainedturbiditic sandstones (Fig. 4, logs III-IV-V). Thefacies are mainly formed of dark-grey, greenish andbrownish sandy clays and marls rich in carbonfragments and with gypsum pebbles, greenish andyellowish fine-grained arenites and silt layers, mas-sive arenites with mollusc shells, marly calcilutites,and lenses of disorganized conglomerates withcalcareous-marly pebbles. A distinctive feature isthe occurrence, near the top of the unit, of someslumped horizons containing polychromatic claysand black shales with scattered siliceous-calcare-ous-marly blocks. In the Vallone del Cerro valley(Fig. 4, log II), silty clays with pebbles of gypsumare present and thick horizons of silty sands andconglomerates are interbedded.

Sandstones of the Torrente Fiumarella are quart-zolithic (Qm49±12 F18±17 Lt33±21); they include abun-dant quartz and feldspar (P/F=0,5; Qm76±15 K12±8P12±8). Aphanitic lithic fragments are dominantlysedimentary (Lm4±9 Lv0±0 Ls96±9), represented byextrabasinal carbonate (micrite, bio-micrite,sparitic, and biosparitic limestone and fossils) andminor siliciclastic fragments. Phaneritic rock frag-ments include also plutonic and metamorphic frag-ments; generally dominant are sedimentary-carbonate types (Rg29±34 Rs65±34 Rm6±3) (Figs. 6 and7). Microfossil associations consist of reworked

planktonic foraminifera and calcareous nanno-plankton species, as well as freshwater ostracods,such as Cyprideis torosa and Candona sp. (Basso etal., 2001, 2002).

The unit consists of slope to basin-plain depos-its; the basin was of the closed-lake type andreceived sporadic coarse detritus input, comingfrom an embryonic alluvial system, which wasdeveloping during emergence of the Apenninechain. The sedimentary lithofacies and their stack-ing patterns suggest repeated transitions fromdeeper to shallower water due to variations of rela-tive base level and of lake-basin infilling, with anoverall deepening trend.

The Anzano Molasse (Crostella and Vezzani,1964) is about 350 m thick and shows an overallupward fining trend (Fig. 4); it can be subdividedinto a lower arenaceous-conglomerate member andan upper arenaceous-pelite member (Matano,2002). The lower member (Fig. 4, log IV-VI-VII-VIII) is composed of granular and pebbly paracon-glomerates in a sandy matrix, and by coarse sand-stones (Figs. 5C–5D). The deposits are typicallymassive or thickly stratified and poorly cemented,locally with continental thin-shelled mollusk shellfragments and carbonized plant fragments. Medium-to coarse-grained sandstones with massive, gradedand laminated textures are present (Fig. 5E). Theupper member (Fig. 4, log III-VI-VII-VIII) consistsof yellow-brown medium to poorly cemented sand-stones, which are medium- to coarse-grained andthinly stratified, and by marly or clayey siltstones,locally rich in carbonized plant fragments andleaf marks. The turbidite sandstones present anerosional basal surface with flute-casts (Fig. 5F);paleocurrent directions are toward N120°–140°(ESE-SE). In the upper member, a discontinuouswhitish tuffite layer (Fig. 5G), formed by 1 or 2 dm-thick strata, is present (Fig. 4, log VI).

The unit consists of various lithofacies of gravitydeposits (cohesionless debris-flows, high-densitypebbly and granular turbidity currents, granular andsandy debris flows, and low-density turbiditycurrents), which form small-scale upward fining andthinning cyclically stacked successions (Matano,2002).

Anzano Molasse Formation sandstones arequartzofeldspathic (Qm44±5 F44±7 Lt12±8), with abun-dant quartz and equal proportions of plagioclase andK-feldspar (P/F=0,5; Qm50±6 K24±4 P26±6). Abun-dance of feldspars, with respect to the TorrenteFiumarella sandstones, suggests increasing contri-

POST-EVAPORITIC SANDSTONES 715

bution from plutonic source areas. Aphanitic lithicfragments (Lm16±21 Lv1±3 Ls83±22) are dominantlysedimentary, both carbonate (extrabasinal) andsiliciclastic fragments (chert, shale and siltstone).Total (phaneritic+aphanitic) rock fragments includevariable proportions of plutonic and sedimentaryfragments. In particular, two subpopulations are evi-dent, one plutonic-rich Rg78±11 Rs7±3 Rm15±11 andone mixed plutonic and sedimentary Rg42±10 Rs46±9Rm12±4 (Figs. 6 and 7).

Volcaniclastic strata (tephra layers) in the upperportions of the Anzano Molasse Formation are com-posed dominantly of neovolcanic detritus as vitricparticles (shards and pumice) (Fig. 7). Crystals arerare and are represented by quartz, sanidine, andplagioclase, and rarely biotite. Chemical analysis,SEM observations, and SEM-EDS microanalysissuggest felsic composition (rhyodacitic to rhyolitic),

confirming the previous study by Di Girolamo et al.(1986).

Intrarenites of the Lago-Mare facies containabundant intrabasinal carbonate particles (ooids,peloids, and bioclast) NCE22±11 CE4±0 CI74±11 andsubordinate extrabasinal noncarbonate and carbon-ate particles. Noncarbonate detritus includesquartz, feldspars, and rare aphanitic lithic frag-ments (Qm52±1 F25±4 Lt24±4; Qm68±2 K20±6 P12±4), aslow-grade metamorphic, sedimentary, and minorphaneritic plutonic rock fragments (Rg16±1 Rs53±1Rm31±3) (Figs. 6 and 7H).

Fossil associations are formed by rare freshwaterostracods, includingCyprideis torosa, Ilyociprisgibba, Candona sp., and Loxoconcha sp., and byMiocene reworked planktonic foraminifera (Globi-gerina multiloba, etc.) and calcareous nannoplank-ton species (Basso et al., 2002; Matano, 2002).

FIG. 6. Ternary diagrams showing sandstones composition of the post-evaporitic units. Mean (circle, diamond, andstar) and standard deviation (polygon). Abbreviations: Qm = monocrystalline quartz; F = feldspars, K+P; Lt = aphaniticlithic fragments and fine-grained polycrystalline quartz), K = K-feldspar; P = plagioclase). Aphanitic lithic and phaner-itic rock fragments in Rg (plutonic), Rs (sedimentary), and Rm (metamorphic). NCE = extrabasinal noncarbonate grains;CE = extrabasinal carbonate grains; CI = intrabasinal carbonate grains.

716 BARONE ET AL.

FIG. 7. Photomicrographs of diagnostic grains of the post-evaporitic units. A. Plutonic rock fragment (Rg). B. Phyllitelithic fragment (Lm). C. Polycrystalline quartz with tectonic fabric (Qp). D. Serpentinite lithic fragment (Lo). E. Volcaniclithic fragment with felsitic granular texture (Lvfg). F. Extrabasinal carbonate as micrite limestone (CE). G. General viewof the arenite studied, evidenced by rounded quartz crystal (Qtz) and extrabasinal carbonate as micrite limestone (CE).H. General view of the Lago-Mare intrarenite.

POST-EVAPORITIC SANDSTONES 717

Sedimentary lithofacies, their stacking patterns,and fossil associations of post-evaporitic depositscan be referred to a mainly freshwater lacustrinebasin with an overall deepening trend, receivingabundant coarse detritus from the thrust-belt. Sub-sequent basinal evolution shows a deeper-waterphase characterized by fine-grained facies of gravitydeposits.

Discussion and ImplicationsProvenance relations and regionalpaleogeographic evolution before andduring the Messinian salinity crisis

The pre-evaporitic history of the southern Apen-nines foreland region has been clearly influenced bycollisional processes since the early Miocene, whenthe Lucanian remnant-ocean basin was closed, andthe Mesomediterranean terrane collided with theAdriatic terrane of the Africa plate (Patacca andScandone, 1989; Doglioni, 1991; Guerrera et al.,1993; Critelli, 1999). Onset of continental collisionand subsequent foreland clastic sedimentation are

dated in the southern Apennines as early Miocene,and accretionary processes continued with high sliprates and uplift rates since the early Tortonian(Patacca et al., 1990; Sgrosso, 1998). During theTortonian, the southern Italian orogenic systemabruptly increased its eastward displacement,deforming and incorporating shallow-marine anddeep-marine domains of the Adria continentalmargin within the thrust belt. As a result of this newthrust-belt architecture, the foreland-basin systemshifted eastward toward the Apulia platform, into anarea previously dominated by pelagic and carbonatesedimentation of the Frigento, Fortore, and Dauniaunits (Fig. 8). Detrital modes for the southern Apen-nines foreland sandstone suites testify to abruptlychanging petrofacies during early evolution of theforeland, the result of accretionary processes andexhumation of crystalline terranes of the Mesomedi-terranean microplate (e.g., the Calabrian Arc), thusgenerating voluminous plutonic-metamorphiclasticsandstones. Since the Tortonian, detrital modeshave been dominantly quartzofeldspathic, havingalso contributions from sedimentary source rocks as

FIG. 8. Paleogeographic sketch of the Apenninic domains during the Miocene. Initial backarc rifting of the Tyrrhe-nian Sea, diverse wedge-top and foredeep depozones, and progressive displacement of the outer front of the chain in thesouthern Apennines foreland region.

718 BARONE ET AL.

carbonate platforms and pelagic rocks that wereassembled within the thrust belt.

During the Messinian, the paleogeography andpaleotectonics of the southern Italian orogenicsystem were characterized by the hundred-kilo-meter-wide thrust belt and several small to medium-size depositional basins on both foreland and back-arc flanks of thrust belt (Fig. 8). Also, the salinitycrisis that occurred during the late Messinian pro-duced interaction between clastic and evaporitesedimentation for many of these basins. From thesyn-rift backarc region to intermontane and forelandregions, evaporite sedimentation occured with, orwas followed by, clastic sedimentation (e.g.,Amantea Basin, Crotone and Rossano basins,Irpinia-Daunia basins; Di Nocera et al., 1975;Critelli, 1999; Matano et al., 2005). Detrital modesduring the Messinian sedimentary history in south-ern Italy are marked by regional quartzofeldspathicpetrofacies, suggesting deep unroofing of theCalabrian Arc (e.g., Critelli and Le Pera, 1995,1998; Critelli, 1999).

All sandstones have plutonic and sedimentarydetritus (Fig. 6). Sedimentary detritus is abundantin all sections, and consists of both carbonate andsiliciclastic particles (Fig. 7). Carbonate detritusincludes both pelagic and shelfal microfacies,suggesting provenance from deformed basinal andplatform sequences assembled within the thrustbelt. These particles suggest a provenance of Meso-zoic to Tertiary strata of the Alburno-Cervati-Pollinoand Monti della Maddalena-Monte Marzano units(pre-Tortonian forebulge zone of the orogenicsystem) and from the Sicilide and Lagonegro(Frigento-Fortore) units (pre-Tortonian backbulge),representing the frontal thrust of the post-Tortonianorogenic system (Fig. 8). The abundance of plutonicand metamorphic detritus suggests a provenancefrom both the accreted Calabrian arc terranes and/orthe recycling of these particles from older clasticunits (i.e., pre-Tortonian clastic wedges), assuggested by the presence of variable percentages ofsiliciclastic debris.

Interplay of the Messinian salinity crisis and tectonics

The late Messinian evolutionary history of theIrpinia-Daunia section of southern Apennines fore-land basin system occurred in two key stages (Fig.9). During stage 1 (Fig. 9B), the region underwent amarked restriction for the first time, which resultedin progressive establishment of anoxic, starved con-

ditions during the pre-evaporitic stage, and then, inmarine evaporite sedimentation, about 100 m inthickness, in marginal portions of the foreland basinduring the early part of the late Messinian (evapor-itic stage). Evaporite deposits (the Monte CastelloEvaporites Formation) are dominated by alterna-tions of clastic reworked gypsum beds, laminatedgypsum, and selenitic gypsum beds. Gypsumformed in a restricted/evaporitic shallow- to deeper-water environment fed by marine waters, accordingto Sr isotopic compositions (Matano et al., 2005).The Monte Castello Evaporites are correlated withthe classical Lower Evaporite sequences, as theyoccur in diverse portions of the Mediterraneanregion.

Transition from stage 1 to stage 2 in the southernApennines foreland basin corresponds to a strongtectonic phase (Decima and Wezel, 1971; Elter etal., 1975; Di Nocera et al., 1976; Torre et al., 1988;Patacca and Scandone, 1989). During the intra-Messinian tectonic phase, the Daunia unit wasdeformed and thrust eastward, forming the frontalsector of the late Messinian thrust wedge, and thepropitious conditions for the evaporitic depositionwere terminated. This led to the migration of fore-land-basin depocenters (DeCelles and Giles, 1996;Fig. 9C) and in marginal settings, to the formation ofan important erosional surface (Roveri et al., 2001).General agreement exists that this erosional surfacedeveloped in a subaerial environment during the1500 m sea-level drop, which led to the completedesiccation of Mediterranean in the intervalbetween 5.59 and 5.50 Ma (Krijgsman et al., 1999).

In the study area, marginal evaporites arecapped by an angular unconformity with evidence ofsubaerial exposure (Matano et al., 2005); this wouldagree with a base-level drop related to desiccation ofthe basin. According to Butler et al. (1995) andRoveri et al. (2001), deposition of marginal lower-type evaporites preceded the complete desiccationof the Mediterranean and was controlled by pre-existing foreland-basin morphology.

In stage 2 (Fig. 9C), proximal portions of the fore-land-basin emerged, the result of the intra-Messin-ian tectonic phase, receiving voluminous clasticalluvial-lacustrine sediments, as suggested also bythe presence of freshwater ostracods in the TorrenteFiumarella and Anzano Molasse units (Fig. 4),which accumulated in a thrust-top basin formed onthe Frigento, Fortore, and Daunia thrust sheets.

The Torrente Fiumarella sandstone suiteincludes a quartzolithic petrofacies containing

POST-EVAPORITIC SANDSTONES 719

FIG

. 9. M

odel

of M

essi

nian

tect

onic

and

str

atig

raph

ic e

vent

s in

the

nort

hern

sec

tor

of th

e so

uthe

rn A

penn

ine

fore

land

bas

in s

yste

m (m

odifi

ed a

fter

Mat

ano

et a

l., 2

005)

.

720 BARONE ET AL.

abundant plutonic and sedimentary detritus (Fig. 6).The petrofacies is controlled by hydrographic-net-work and basin reorganization related to the salinitycrisis and local tectonics.

The Anzano Molasse sandstones are typical ofthe general quartzofeldspathic petrofacies, abun-dant plutonic and medium-high-grade metamorphicdetritus, and locally important sedimentary contri-butions (Fig. 6) derived from the inner carbonateplatform of the Alburno-Cervati-Pollino units andtheir margins (Monti della Maddalena–Monte Mar-zano units), and from pelagic sequences of the Sicil-ide Complex and Lagonegro basin units (Fig. 8).

Intrarenites of the Lago-Mare succession (Fig. 4)contain abundant intrabasinal carbonate particles(Fig. 6) that are related to the presence of layers veryrich in ostracoda assemblages, a common biofaciesin the Lago Mare event (Bonaduce and Sgarrella,1999; Gliozzi, 1999). This event is recorded inthe whole Apenninic-Maghrebian foreland-basinsystem, in the Tyrrhenian area and in the westernand eastern Mediterranean, suggesting completeMediterranean isolation from the ocean (Hsü et al.,1977).

A sudden change in hydrology of the southernApennines foreland region occurred in the latestMessinian, when a dominantly freshwater bodyreplaced the marine waters, apparently withoutchange in water depth. This new hydrologic regimeis recorded in deep-water basin successions both ofthe northern Apennines (Roveri et al., 2001) and ofthe southern Apennines by organic-rich euxinic lay-ers with gypsum characterized by lower Sr isotopicratios (Matano et al., 2005).

Conclusions

During the Messinian, the southern Apenninesexperienced intense accretion and uplift. Post-evaporitic sandstones in the Irpinia-Daunia sectorof the southern Apennines foreland-basin systemrecord effects of both foreland evolution and theMessinian salinity crisis. Abrupt change from hemi-pelagic and calciturbidite sedimentation to evapor-ite and post-evaporitic clastic sedimentationresulted from the interplay between tectonics andsea-level changes.

Stratigraphic and petrologic studies of theMessinian succession in the Irpinia-Daunia portionsof the southern Apennines foreland-basin systempermit the following conclusions:

1. Evidence suggests the progressive establish-ment of anoxic, starved conditions during the pre-evaporitic stage and a permanent marine connectionduring the evaporitic stage, dominated by reworkedgypsum and laminated selenitic gypsum (MonteCastello Evaporite Formation) in the Daunia unitdomain.

2. The presence of an angular unconformity witherosional features at the base of the post-evaporiticdeposits attests to tectonic deformation of the Dau-nia unit within the thrust belt and its emergence.

3. The presence of continental alluvial andlacustrine deposits (Anzano Molasse and TorrenteFiumarella formations) in the post-evaporiticsequence attests to the influence Lago-Mare eventsand tectonic foreland evolution have exerted onpaleohydrography and basin paleogeography.

Detrital modes document complex provenancerelations with late Messinian accreted terranes ofthe southern Apennines. All sandstones have abun-dant plutonic and sedimentary detritus. Carbonatedetritus includes both pelagic and shelfal microfa-cies, suggesting provenance from deformed basinaland platform sequences assembled within the thrustbelt. The abundance of plutonic and metamorphicdetritus in these sandstones suggests derivationfrom both accreted Calabrian arc terranes and recy-cling from older clastic sequences.

Lithology and facies arrangement of both pre-evaporitic deposits and primary evaporites of thesouthern Apennines foredeep are similar to those ofthe northern Apennines evaporites (Vai and RicciLucchi, 1977) and the “lower evaporites” of Sicily(Decima and Wezel, 1971). The “upper evaporites”of Sicilian basins are not present in the northern andsouthern Apennines foredeep successions, whichare characterized by post-evaporitic clastic depos-its. Study of the nonmarine Anzano-Fiumarellabasin may provide useful data about the evolution ofsimilar sedimentary basins; nonetheless, the studiedsequences provide an example of the effects of theinterplay between tectono-stratigraphic evolution ofa foreland basin and the salinity-crisis in the sedi-mentary record.

Acknowledgments

We are very grateful to Ray Ingersoll, who kindlyreviewed and improved the final version of themanuscript. We are grateful to J. M. Rouchy, J. P.Réhault, and M. Roveri for discussions and review-ing an earlier version of the manuscript. The

POST-EVAPORITIC SANDSTONES 721

research was supported by funds (ex-60%) of theItalian Ministero dell’Università e della RicercaScientifica, project “Paleogeographic and Paleotec-tonic Evolution of the Southern Italian OrogenicSystem and Their Correlations with the Circum-Mediterranean Orogeny” (Resp. S. Critelli), and bythe COFIN-PRIN 2003 project “eventi stratigraficie paleogeografia del Messiniano e del Pliocenenell’Appennino molisano-campano” (Resp. S. DiNocera).

REFERENCES

Aguirre, J., and Sànchez-Almazo, I. M., 2004, TheMessinian post-evaporitic deposits of the Gafares area(Almerìa-Nìjar basin, SE Spain): A new view of theLago-Mare facies: Sedimentary Geology, v. 168, p. 71–95.

Amore, O., Basso, C., Ciampo, G., Ciarcia, S., Di Donato,V., Di Nocera, S., Esposito, P., Matano, F., Staiti, D.,and Torre, M., 1998, Nuovi dati stratigrafici sulPliocene affiorante tra il fiume Ufita ed il torrente Cer-varo (Irpinia, Appennino meridionale): Bollettino dellaSocietà Geologica Italiana, v. 117, p. 455–466.

Bassetti, M. A., Ricci Lucchi, F., and Roveri, M., 1994,Physical stratigraphy of the Messinian post-evaporiticdeposits in central-southern Marche area Apennines,Central Italy: Memorie della Società Geologica Ital-iana, v. 48, p. 275–288.

Basso, C., Ciampo, G., Ciarcia, S., Di Nocera, S., Matano,F., and Torre, M., 2002, Geologia del settore irpino-dauno dell’Appennino meridionale: Unità meso-ceno-zoiche e vincoli stratigrafici nell’evoluzione tettonicamio-pliocenica: Studi Geologica: Camerti-nuova serie,v. 2, p. 7–26.

Basso, C., Di Nocera, S., Esposito, P., Matano, F., Russo,B., and Torre, M., 2001, Stratigrafia delle successionisedimentarie evaporitiche e post-evaporitiche delMessiniano superiore in Irpinia settentrionale (Appen-nino meridionale): Bollettino della Società GeologicaItaliana, v. 120, p. 211–231.

Basso, C., Di Nocera, S., Matano, F., and Torre M., 1996,Successioni sedimentarie del Messiniano superiore edel Pliocene inferiore in Irpinia settentrionale: Bollet-tino della Società Geologica Italiana, v. 115, p. 701–715.

Bellanca, A., Caruso, A., Ferruzza, G., Neri, R., Rouchy,J. M., Sprovieri, M., and Blanc-Valleron, M. M., 2001,Transition from marine to hypersaline conditions in theMessinian Tripoli Formation from the marginal areasof the central Sicilian Basin: Sedimentary Geology, v.140, p. 87–105.

Bonaduce, G., and Sgarrella, F., 1999, Paleoecologicalinterpretation of the latest Messinian sediments from

southern Sicily (Italy): Memorie della Società Geolog-ica Italiana, v. 54, p. 83–92.

Butler, R. W. H., and Grasso, M., 1993, Tectonic controlson base-level variations and depositional sequenceswithin thrust-top and foredeep basins: Examples fromthe Neogene thrust belt of central Sicily: BasinResearch, v. 5, p. 137–151.

Butler, R. W. H., Lickorish, W. H., Grasso, M., and Ram-berti, L., 1995, Tectonics and sequence stratigraphy inMessinian basins, Sicily: Constraints on the initiationand termination of the Mediterranean salinity crisis:Geological Society of America Bulletin, v. 107, p.425–439.

Cavazza, W., and De Celles, P. G., 1998, Upper Messiniansiliciclastic rocks in southeastern Calabria (southernItaly): Palaeotectonic and eustatic implications for theevolution of the central Mediterranean region: Tec-tonophysics, v. 298, p. 223–241.

Ciaranfi, N., Dazzaro, L., Pieri, P., Rapisardi, L., andSardella, A., 1973, Geologia della zona compresa fraBisaccia (Av): Memorie della Società Geologica Ital-iana, v. 12, p. 279–315.

Ciarapica, G., and Passeri, L., 1980, Contributions onevaporites diagenesis: Géologie Méditerranéenne, v. 7,no. 1, p. 43–48.

Ciarcia, S., Di Nocera, S., Matano, F., and Torre, M., 2003,Evoluzione tettono-sedimentaria e paleogeografica deidepocentri “wedge-top” nell’ambito del “forelandbasin system” pliocenico dell’Appennino meridionale(settore irpino-dauno): Bollettino della Società Geolog-ica Italiana, v. 122, p. 117–138.

Cipollari, P., Cosentino, D., and Gliozzi, E., 1999a, Exten-sion- and compression-related basins in central Italyduring the Messinian Lago-Mare event: Tectonophys-ics, v. 315, p. 163–185.

Cipollari, P., Cosentino, D., and Praturlon, A., 1999b,Thrust-top lacustrine-lagoonal basin development inaccretionary wedges: late Messinian (Lago-Mare)episode in the central Apennines (Italy): Palaeogeog-raphy, Palaeoclimatology, Palaeoecology, v. 151, p.149–166.

Clauzon, G., Suc, J. P., Gauthier, F., Berger, A., andLoutre, M. F., 1996, Alternate interpretation of theMessinian salinity crisis: Controversy resolved?: Geol-ogy, v. 24, p. 363–366.

Colalongo, M. L., Cremonini, G., Farabegoli, E., Sartori,R., Tampieri, R., and Tomadin, L., 1978, Palaeoenvi-ronmental study of “Colombacci” Formation in Roma-gna (Italy): The Cella section: Memorie della SocietàGeologica Italiana, v. 16, p. 197–216.

Critelli, S., 1999, The interplay of lithospheric flexure andthrust accomodation in forming stratigraphicsequences in the southern Apennines foreland basinsystem, Italy: Rendiconti Accademia Nazionale deiLincei–Scienze Fisica e Naturali, v. 10, p. 257–326.

Critelli, S., and Le Pera, E., 1995, Tectonic evolution ofthe Southern Apennines thrust-belt (Italy) as reflected

722 BARONE ET AL.

in modal compositions of Cenozoic sandstone: Journalof Geology, v. 103, p. 95–105.

Critelli, S., and Le Pera, E., 1998, Post-Oligocene sedi-ment-dispersal systems and unroofing history of theCalabrian Microplate, Italy: International GeologyReview, v. 40, p. 609–637.

Crostella, A., and Vezzani, L., 1964, La geologiadell’Appennino foggiano: Bollettino della Società Geo-logica Italiana, v. 83, p. 121–142.

D’Argenio, B., Pescatore, T., and Scandone, P., 1975,Structural pattern of the Campania-Lucania Apen-nines, in Ogniben L., Parotto, M., and Praturlon, A.,eds., Structural model of Italy: C.N.R.: Quaderni de LaRicerca Scientifica, v. 90, p. 313–327.

Dazzaro, L., Iannone, A., Moresi, M., Rapisardi, L., andRomeo, M., 1988, Stratigrafia, sedimentologia egeochimica delle successioni messiniane dell’Irpiniaal confine con la Puglia: Memorie della Società Geo-logica Italiana, v. 41, p. 841–859.

Decima, A., and Wezel, F. C., 1971, Osservazioni sulleevaporiti messiniane della Sicilia centro-meridionale:Rivista Mineralogica Siciliana, v. 22, p. 130–132.

Decima, A., and Wezel, F. C., 1973, Late Miocene evapor-ites of the Central Sicilian Basin: Initial Report, DSDPLeg 13, p. 1234–1240.

De Celles, P. G., and Giles, K. A., 1996, Foreland basinsystems: Basin Research, v. 8, p. 105–123.

Delrieu, B., Rouchy, J. M., and Foucault, A., 1993, La sur-face d’érosion fini-messinienne en Crète centrale(Grèce) et sur le pourtour méditerranéen: Raports avecla crise de salinité méditerranéenne: C.R. LesComptes Rendus de l’Académie des Sciences, série II,p. 316, 527–533.

Dessau, G., 1952, Contributo alla geologia della zona diAriano Irpino (provincie di AV e FG): BollettinoServizio Geologico d’Italia, v. 74, p. 4–42.

Dickinson, W. R., 1970, Interpreting detrital modes ofgraywacke and arkose: Journal of Sedimentary Petrol-ogy, v. 40, p. 695–707.

Di Girolamo, P., Nardi, G., Ortolani, F., Stanzione, D., andTorre, M., 1986, The petrological and geodynamic sig-nificance of late miocene-pliocene tuffite from theSouthern Apennines (Italy): Neues Jahrbuch derMineralogie, Abhandlungen, v. 155, no. 2, p. 203–218.

Di Nocera, S., Matano, F., and Torre M., 2002, Le unità“sannnitiche” Auct. (Appennino centro-meridionale):Rassegna delle correnti interpretazioni stratigrafiche epaleogeografiche e nuove ipotesi con l’introduzionedell’Unità di Frigento: Studi Geologici Camerti (nuovaserie), v. 1, p. 87–102.

Di Nocera, S., Ortolani, F., Russo, M., and Torre, M., 1975,Successioni sedimentarie messiniane e limiteMiocene–Pliocene nella Calabria settentrionale:Bollettino della Società Geologica Italiana v. 93, p.575–607.

Di Nocera, S., Ortolani, F., and Torre, M., 1976, Fasetettonica messiniana nell’Appennino meridionale:

Bollettino della Società dei Naturalisti in Napoli, v. 84,p. 1–17.

Doglioni, C., 1991, A proposal for the kinematic model-ling of W-dipping subductions–possible applicationsto the Tyrrhenian-Apennines system: Terra Nova, v. 3,p. 423–434.

Elter, P., Giglia, G., Tongiorgi, M., and Trevisan, L., 1975,Tensional and compressional areas in the recent(Tortonian to Present) evolution of the Northern Apen-nines: Bollettino di Geofisica Teorica e Applicata, v.17, p. 1–65.

Fortuin, A. R., Kelling, J. M. D., and Roep, T. B., 1995,The enigmatic Messinian–Pliocene section of Cuevasdel Almanzora (Vera Basin, SE Spain) revisited—erosional features and strontium isotope ages: Sedi-mentary Geology, v. 97, p. 177–201.

Gazzi, P., 1966, Le arenarie del flysch sopracretaceodell’Appennino modenese; correlazioni con il Flyschdi Monghidoro: Mineralogica Petrographica Acta, v.12, p. 69–97.

Gliozzi, E., 1999, A late Messinian brackish water ostra-cod fauna of Paratethyan aspect from Le VicenneBasin: Palaeogeography, Palaeoclimatology, Palaeo-ecology, v. 151, nos. 1/3, p. 191–208.

Guerrera, F., Martin-Algarra, A., and Perrone, V., 1993,Late Oligocene syn-/late-orogenic successions inWestern and Central Mediterranean chains from theBetic Cordillera to the Southern Apennines: TerraNova, v. 5, p. 525–544.

Hsü, K., Cita, M. B. and Ryan, W. B. F. 1973, The origin ofMediterranean evaporates: Initial Report DSDP, v. 13,p. 1203–1231.

Hsü, K., Montadert, L., Bernoulli, D., Cita, M. B., Erick-son, A., Garrison, R. E., Kidd, R. B., Melieres, F.,Muller, C., and Wright, R., 1977, History of the Medi-terranean salinity crisis: Nature v. 267, p. 399–403.

Ingersoll, R. V., Bullard, T. F., Ford, R. L., Grimm, J. P.,Pickle, J. D., and Sares, S. W., 1984, The effect ofgrain size on detrital modes: a test of the Gazzi-Dickin-son point-counting method: Journal of SedimentaryPetrology, v. 54, p. 103–116.

Krijgsman, W., Hilgen, F. J., Raffi, I., Sierro, F. J., andWilson, D. S., 1999, Chronology, causes, and progres-sion of the Messinian salinity crisis: Nature, v. 400,6745, p. 652–655.

Martin, J. M., and Braga, J. C., 1994, Messinian events inthe Sorbas Basin in southeastern Spain and theirimplications in the recent history of the Mediterra-nean: Sedimentary Geology, v. 90, p. 257–268.

Matano, F., 2002, Le Molasse di Anzano nell’evoluzionetettono-sedimentaria messiniana del margine occiden-tale della microzolla apula nel settore irpino-daunodell’orogene sud-appenninico: Memorie della SocietàGeologica Italiana, v. 57, p. 209–220.

Matano, F., Barbieri, M., Di Nocera, S. and Torre, M.,2005, Stratigraphy and strontium geochemistry ofMessinian evaporite-bearing successions of the south-

POST-EVAPORITIC SANDSTONES 723

ern Apennines foredeep, Italy: Implications for theMediterranean “salinity crisis” and regional palaeo-geography: Palaeogeography, Palaeoclimatology,Palaeoecology, v. 217, p. 87–114.

Matano, F., and Di Nocera, S., 2001, Geologia del settorecentrale dell’Irpinia (Appennino meridionale): Nuovidati e interpretazioni: Bollettino della Società Geolog-ica Italiana, v. 120, p. 3–14.

Mostardini, F., and Merlini, S., 1986, Appennino centro-meridionale. Sezioni geologiche e proposta di modellostrutturale: Memorie della Società Geologica Italiana,v. 35, p. 177–202.

Müller, D. W., and Mueller, P. A., 1991, Origin and age ofthe Mediterranean Messinian evaporites: Implicationsfrom Sr isotopes: Earth and Planetary Science Letters,v. 107, p. 1–12.

Orszag-Sperber, F., Rouchy, J. M., and Blanc-Valleron,M. M., 2000, La transition Messinien–Pliocène enMéditerranée orientale (Chypre): La période du Lago-Mare et sa signification: C.R. Les Comptes Rendus del’Académie des Sciences, v. 331, p. 483–489.

Patacca, E., Sartori, R., and Scandone, P., 1990, Tyrr-henian basin and Apenninic arcs: Kinematic relationssince late Tortonian times: Memorie della Società Geo-logica Italiana, v. 45, p. 425–451.

Patacca, E., Sartori, R., and Scandone, P., 1993, Tyrr-henian basin and Apenninic. Kinematic evolution andrelated dynamic constraints, in Boschi, E. et al., eds.,Recent evolution and seismicity of the MediterraneanRegion: Dordrecht, Netherlands, Kluwer AcademicPublication, p. 161–171.

Patacca, E., and Scandone, P., 1989, Post-Tortonianmountain building in the Apennines. The role of thepassive sinking of a relict lithosperic slab, in Boriani,A., Bonafede, M., Piccardo, G. B., and Vai, G. B., eds.,The lithosphere in Italy. Advances in Earth SciencesResearch, Italian National Committee, InternationalLithosphere Program, Mid-term Conference Proceed-ings, Roma: Atti Convegno Lincei, v. 80, p. 157–176.

Peryt, T. M., 1996, Sedimentology of Badenian (middleMiocene) gypsum in eastern Galicia, Podolia andBukovina (West Ukraine): Sedimentology, v. 43, p.571–588.

Pescatore, T., Di Nocera, S., Matano, F., and Pinto, F.,2000, L’unità del Fortore nel quadro della geologia delsettore orientale dei Monti del Sannio (Appenninomeridionale): Bollettino della Società Geologica Ital-iana, v. 119, p. 587–601.

Playà, E., Ortì, F., and Rosell, L., 2000, Marine to non-marine sedimentation in the upper Miocene evaporitesof the Eastern Betics, SE Spain: Sedimentological andgeochemical evidences: Sedimentary Geology, v. 133,p. 135–166.

Riding, R., Braga, J. C., Martin, J. M., and Sanchez-Almazo, I. M., 1998, Mediterranean Messinian salinitycrisis: Constraints from a coeval marginal basin,

Sorbas, southeastern Spain: Marine Geology, v. 146, p.1–20.

Riding, R., Braga, J. C., and Martin, J. M., 1999, LateMiocene Mediterranean desiccation: Topography andsignificance of the “salinity crisis” erosion surface on-land in southeast Spain: Sedimentary Geology, v. 123,p. 1–7.

Rouchy, J. M., Orzag-Sperber, F., Blanc-Valleron, M. M.,Pierre, C., Riviére, M., Comboriou-Nebout, N., andPanaydes, I., 2001, Palaeoenvironmental changes atthe Messinian–Pliocene in the eastern Mediterranean(Southern Cyprus Basin): Significance of the Messin-ian Lago-Mare: Sedimentary Geology, v. 145, p. 93–117.

Roure, F., Casero, P., and Vially, R., 1991, Growthprocesses and melange formation in the southernApennines accretionary wedge: Earth and PlanetaryScience Letters, v. 102, p. 395–412.

Roveri, M., Bassetti, M. A., and Ricci Lucchi, F., 2001,The Mediterranean Messinian salinity crisis: AnApennine foredeep perspective: Sedimentary Geology,v. 140, p. 201–214.

Roveri, M., Manzi, V., Bassetti, M. A., Merini, M., andRicci Lucchi, F., 1998, Stratigraphy of the Messinianpost-evaporitic stage in eastern-Romagna (northernApennines, Italy): Giornale di Geologia, v. 60, p. 19–142.

Roveri, M., Manzi, V., Ricci Lucchi, F., and Rogledi, S.,2003, Sedimentary and tectonic evolution of the Venadel Gesso basin (Northern Apennines, Italy): Implica-tion for the onset of the Messinian salinity crisis: Geo-logical Society of America Bulletin, v. 115, p. 387–405.

Schreiber, B. C., and Decima, A., 1976, Sedimentaryfacies produced under evaporitic environments: Areview: Memorie della Società Geologica Italiana, v.16, p. 111–126.

Schreiber, B. C., Friedman, G. M., Decima, A., andSchreiber, E., 1976, Depositional environment ofUpper Miocene (Messinian) evaporite deposits of theSicilian Basin: Sedimentology, v. 23, p. 729–760.

Sgrosso, I., 1998, Possibile evoluzione cinematica mioce-nica nell’orogene centro-sud appenninico: BollettinoSocietà Geologica Italiana, v. 117, p. 679–724.

Torre, M., Di Nocera, S., and Ortolani F., 1988, Evoluzionepost-tortoniana nell’Appennino meridionale: Memoriedella Società Geologica Italiana, v. 41, p. 47–56.

Vai, G. B., 1997, Cyclostratigraphic estimate of theMessinian stage duration, in Montanari, A., Odin,G. S., and Coccioni, R., eds., Miocene stratigraphy: Anintegrated approach: Amsterdam, The Netherlands,Elsevier Science, p. 463–476,

Vai, G. B., and Ricci Lucchi, F., 1977, Algal crusts,autochthonous and clastic gypsum in a cannibalisticevaporite basin: A case history from the Messinian ofNorthern Apennines: Sedimentology, v. 24, p. 211–244.

724 BARONE ET AL.

Zuffa, G. G., 1985, Optical analyses of arenites: Influenceof methodology on compositional results, in Zuffa,G. G., ed., Provenance of arenites: Dordrecht, The

Netherlands, Reidel, NATO Advanced Study InstituteSeries 148, p. 165–189.